What does "indent -kr -l120 -br -ce -npsl -nut -i4 *.[hc]" mean for Makefile?

[thutt]

孙世龙 sunshilong writes:
 > Hi,
 > 
 > As the subject, the related Makefile (and project) is on
 > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Femeryberger%2FMalloc-Implementations%2Fblob%2Fmaster%2Fallocators%2FTLSF%2FTLSF-2.4.6%2Fsrc%2FMakefile&data=02%7C01%7Cthutt%40vmware.com%7C8a86f768042046f8f1e408d841e0bb0f%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C637331780772127600&sdata=XdJ9SuMNKq1xurEOYpVcqUbcXTSFsJugmez06w460Ek%3D&reserved=0
 > 
 > Could somebody shed some light on this question?
 > I would be grateful to have some help.

 It means nothing to Make.  It's a recipe (aka 'command') that is
 executed each time the 'indent' target is invoked.